So, in a desperate bid to do SOMETHING about the consistent crash on launch bug, I've deleted the local files and re-downloaded the game anew. Now I am getting Steam-Error saying "The game is currently unavailable, please try again at another time". What the heck is going on?

Steam is garbage, half the time I can't even log into my steam account because of wierd connectivity issues my ISP has with them. Next time you log into Steam just make sure you tell it to go to offline mode, that way you won't have to worry about dealing with them anymore.

You should search steam tech support for solutions to this issue.

Steam does that to me sometimes, for me it starts after trying again.